板块汇聚带的造山和重力垮塌作用及其力学成因:以雅鲁藏布江-喜马拉雅山汇聚带为例   总被引：5，自引：0，他引：5  

王二七  王刚  樊春  石许华 《地学前缘》2006,13(4):18-26

从大洋底部磁异常条带的宽度变化可以看出,大洋的扩张速率是时常变化的,这种变化与板块俯冲角度的变化一样,对板块汇聚带的应力和应变场有重要的控制作用。中国存在众多不同特征、不同年代的板块汇聚带,根据其中发生的构造作用可以反演汇聚带在板块扩张速率和俯冲角度控制下的演化。有着巨大高差的喜马拉雅山构造带和雅鲁藏布江缝合带在喜马拉雅山东、西构造结逐渐交汇在一起,其平均海拔高度随之增大而宽度不断变小。喜马拉雅山中段的推覆发生在中新世早期,在推覆的过程中,其北缘沿藏南拆离系还发生了大规模的南北向伸展。这表明在中新世前,在雅鲁藏布江缝合带和喜马拉雅山之间可能存在一个规模很大的造山带,在这里称之为喜马拉雅山—雅鲁藏布江造山带,它在中新世初发生了垮塌。作为这个造山带的前缘,喜马拉雅山中段发生向南的推覆,这就是喜马拉雅山中段的推覆时间要远远滞后于印度和欧亚大陆的碰撞时间的原因。造山带的垮塌可能是印度与欧亚大陆间水平汇聚速率的突然减小造成的。发生在古近纪的日本海和中国的松辽盆地的弧后扩张与喜马拉雅山—雅鲁藏布江造山带的重力垮塌作用可以对比,可能是太平洋和欧亚大陆汇聚速率的突然减小造成的。在白垩纪,太平洋和欧亚大陆汇聚速率很大,所以,欧亚大陆东缘,包括日本海和中国的松辽盆地,在当时可能是规模很大的造山带。位于秦岭南侧,上覆在四川盆地之上的大巴山推覆带的形成机制与喜马拉雅山在中新世的推覆成因类似,与晚白垩世—古近纪秦岭的垮塌有成因关联。秦岭的垮塌可能是华南—华北汇聚速率减小造成的,在此之前秦岭要比现今高得多。  相似文献   

基于NPP-VIIRS数据的喜马拉雅山北坡典型湖泊湖冰提取分析     

孙皓  李传华  姚晓军 《冰川冻土》2021,43(1):70-79

现阶段使用遥感数据监测湖冰物候特征已成为主要的技术手段.NPP-VIIRS是一个较新的卫星数据,它具有空间分辨率较高、波段数多、重访周期短等优点,使用该数据提取湖冰信息是对该领域的一个有益补充.基于NPP-VIIRS数据利用阈值法对拉昂错、玛旁雍错、佩枯错、普莫雍错等典型湖泊进行湖冰提取.获得四个湖泊逐日的冻结百分比,...  相似文献   

1990-2015年喜马拉雅山东段中国和不丹边境地区冰川变化研究          下载免费PDF全文

王晶  杨太保  冀琴  秦艳  胡凡盛 《干旱区地理》2019,42(3):542-550

利用Landsat影像,EDM影像等数据资料,使用遥感图像处理及目视解译方法提取了喜马拉雅山东段中国与不丹边境地区冰川从1990—2015年4期边界,研究其与气温降水变化关系,并选取特定冰川,对其表面流速进行估算。研究表明：1990—2015年,该地区冰川退缩速率达0.43%·a^-1,并且冰川年退缩率逐渐增大,表明冰川消融速度逐渐加快。该时段内,气温呈现明显上升趋势,导致了冰川的快速消融。通过对冰川表面流速的估算,得出中国与不丹边境地区研究选取的冰前湖对冰川流速具有促进作用,加速冰川消融。  相似文献   

NCEP/NCAR 再分析资料在喜马拉雅山-青藏高原气象研究中的可行性分析     

谢爱红  任贾文  秦翔  康世昌 《地理学报(英文版)》2007,17(4):421-430

Due to the difficult logistics in the extreme high elevation regions over the Himalayas and Tibetan Plateau, the observational meteorological data are very few. In 2003, an automatic weather station was deployed at the northeastern saddle of Mt. Nyainqentanglha (NQ) (30°24′44.3″ N, 90°34′13.1″ E, 5850 m a.s.l.), the southern Tibetan Plateau. In 2005, another station was operated at the East Rongbuk Glacier Col (28°01′0.95″ N, 86°57′48.4″ E, 6523 m a.s.l.) of Mt. Qomolangma. Observational data from the two sites have been compared with the reanalysis data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR), reliability of NCEP/NCAR reanalysis data has been investigated in the Himalayas/Tibetan Plateau region. The reanalysis data can capture much of the synoptic-scale variability in temperature and pressure, although the reanalysis values are systematically lower than the observation. Furthermore, most of the variability magnitude is, to some degree, underestimated. In addition, the weather event extracted from the NCEP/NCAR reanalyzed pressure and temperature prominently appears one day ahead of the observational data on Mt. Qomolangma, while on Mt. NQ it occurs basically in the same day.  相似文献   

Feasibility Comparison of Reanalysis Data from NCEP-Ⅰ and NCEP-Ⅱ in the Himalayas     

XIE Aihong  REN Jiawen  QIN Xiang  KANG Shichang 《山地科学学报》2009,6(1):56-65

Mt. Everest is often referred to as the earth＇s ＇third＇ pole. As such it is relatively inaccessible and little is known about its meteorology. In 2005, an automatic weather station was operated at North Col （28°1′ 0.95＂ N, 86°57′ 48.4＂ E, 6523 m a.s.l.） of Mt. Everest. Based on the observational data, this paper compares the reanalysis data from NCEP/NCAR （hereafter NCEP-Ⅰ） and NCEP-DOE AMIP-Ⅱ （NCEP- Ⅱ）, in order to understand which reanalysis data are more suitable for the high Himalayas with Mr. Everest region. When comparing with those from the other levels, pressure interpolated from 500 hPa level is closer to the observation and can capture more synoptic-scale variability, which may be due to the very complex topography around Mt. Everest and the intricately complicated orographic land-atmosphereocean interactions. The interpolation from both NCEP-Ⅰ and NCEP-Ⅱ daily minimum temperature and daily mean pressure can capture most synopticscale variability （r〉0.82, n=83, p〈0.001）. However, there is difference between NCEP-Ⅰ and NCEP-Ⅱ reanalysis data because of different model parameterization. Comparing with the observation, the magnitude of variability was underestimated by 34.1%, 28.5 % and 27.1% for NCEP-Ⅰ temperature and pressure, and NCEP-Ⅱ pressure, respectively, while overestimated by 44.5 % for NCEP-Ⅱ temperature. For weather events interpolated from the reanalyzed data, NCEP-Ⅰ and NCEP-Ⅱ show the same features that weather events interpolated from pressure appear at the same day as those from the observation, and some events occur one day ahead, while most weather events and NCEP-Ⅱ temperature interpolated from NCEP-Ⅰ happen one day ahead of those from the observation, which is much important for the study on meteorology and climate changes in the region, and is very valuable from the view of improving the safety of climbers who attempt to climb Mt. Everest.  相似文献   

珠穆朗玛峰的由来     

尚巾 《测绘通报》2005,(10):6-6

耸立在我国西南边陲的喜马拉雅山,是地球上最长、最高、最年轻的山脉.它全长2400多千米,南北宽约200多千米,峰峦重迭,犹如凝固的万顷波涛.世界上第一高峰--珠穆朗玛峰,位于我国与尼泊尔交界处,它像一座巨型的金字塔,巍然屹立在白雪皑皑的喜马拉雅山的群峰之上.  相似文献   

喜马拉雅造山带的构造不对称演化   总被引：22，自引：6，他引：22  

李德威 《地球科学》1992,17(5):539-545

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西藏更新世冰川作用与冰期的开始——一个自循环假说     

Matthias Kuhle 《第四纪研究》1992,12(2):166-166

十次考察任务期间,我们获得了西藏及其周围山地冰川最大规模的新资料。在喜马拉雅山和喀喇昆仑山南侧低至890m和980m的海拔高度上发现冰碛物。在青藏高原北坡的祁连山,冰碛物发现于2300m的海拔高度。在喀喇昆仑山、Aghil和昆仑山北坡,冰碛物也低达1900m。对冰漂砾的放射性分析表明,青藏高原南部和中部古冰体厚度至  相似文献   

西藏喜马拉雅变质岩东部的变质作用特征     

王天武 《西藏地质》1994,(1):150-160

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Distribution of borehole temperature at four high-altitude alpine glaciers in Central Asia     

Yaping Liu  Shugui Hou  Yetang Wang  Linlin Song 《山地科学学报》2009,6(3):221-227

The distribution of borehole temperature at four high-altitude alpine glaciers was investigated. The result shows that the temperature ranges from -13.4℃ to -1.84℃, indicating the glaciers are cold throughout the boreholes. The negative gradient （i.e., the temperature decreasing with the increasing of depth） due to the advection of ice and climate warming, and the negative gradient moving downwards relates to climate warming, are probably responsible for the observed minimum temperature moving to lower depth in boreholes of the Gyabrag glacier and Miaoergou glacier compared to the previously investigated continental ice core borehole temperature in West China. The borehole temperature at 10m depth ranges from -8.0℃ in the Gyabrag glacier in the central Himalayas to -12.9℃ in the Tsabagarav glacier in the Altai range. The borehole temperature at 10 m depth is 3-4 degrees higher than the calculated mean annual air temperature on the surface of the glaciers and the higher 10 m depth temperature is mainly caused by the production of latent heat due to melt-water percolation and refreezing. The basal temperature is far below the melting point, indicating that the glaciers are frozen to bedrock. The very low temperature gradients near the bedrock suggest that the influence of geothermal flux and ice flow on basal temperature is very weak. The low temperature and small velocity of ice flow of glaciers are beneficial for preservation of the chemical and isotopic information in ice cores.  相似文献